<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS基础</title>
    <style>
        /* 写CSS代码的地方 */

        .box1 {
            /* 宽 */
            width: 100px;
            /* 高 */
            height: 100px;
            /* 背景颜色 */
            background-color: darkorange;
        }

        .box2 {
            width: 100px;
            height: 100px;
            background-color: green;
            /* 边框 */
            border: 5px solid blue;
        }

        .container {
            width: 300px;
        }
    </style>
</head>

<body>


    <div class="box1 container"></div>
    <div class="box2 container"></div>
    <div class="box3"></div>


</body>

</html>